The invention relates broadly to a machine for automatically opening a filled bag and emptying the contents of the bag. More specifically, the machine described herein slits a filled bag to divide it into sections, empties the bag, and disposes of the bag sections.
Various materials in powder or granular form are packed in bags for commercial or domestic use. Some of these bagged materials, such as asbestos, are of a dusty or noxious nature. To prevent the dusty material from contaminating the atmosphere, where it can be hazardous to plant workers and detrimental to equipment, there are machines available that can open the filled bags and empty the contents within a closed system.
An example of such a machine is an automatic bag slitting machine, which is manufactured by Bel-Tyne International, Inc., of York, Pa. In a typical operation of the machine, a filled bag is automatically centered between rotating drums equipped with retractable spikes. As the filled bag moves into contact with the drums, a cam mechanism causes the spikes to emerge from inside the drum and to impale the filled bag. The spikes grip the bag and move it downwardly onto a reciprocating cutter blade. The blade cuts the bag completely in half (two sections), to empty the contents into a collector unit. As the bag continues to move through the machine, the two separated bag sections are drawn around each drum. When the rotating drums reach a given point, the spikes retract back into the drum. The intended purpose of retracting the spikes is to permit each bag section to release from its drum, so it can drop into a disposal unit.
The machine described above has certain drawbacks, which make the bag-opening operation less than satisfactory. One of the problems is caused by the design of the spikes. For example, each drum has only a few spikes, and they are of large diameter. This makes it difficult for the spikes to pierce the bag section and hold onto it. The result is an inconsistent cutting and tearing of the empty bag sections, which causes parts of each bag to fall into the collector unit along with the contents of the bag. Another problem is caused when the tips of the spikes don't pull back into the drum far enough to completely release the empty bag section. When this happens, the bag sections can become entangled in the moving cutter blade, which can cause the cutter mechanism to stop: and usually, pieces of the bag will fall into the collector unit.